SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  (
    CASE WHEN descr1.cp_st_h1 <> '' THEN descr1.cp_st_h1 ELSE descr1.product END
  ) AS product, 
  companies.company as company_name, 
  products.product_type, 
  products.parent_product_id, 
  descr1.cp_hash_template_as_timestamp_value, 
  1 as instock_marker, 
  IF(
    products.product_type = 'V', 
    IF (
      mccd__variation_stocks.parent_product_id IS NULL, 
      0, 1
    ), 
    IF(
      products.amount > 0, 
      1, 
      IF(products.tracking = 'D', 1, 0)
    )
  ) as instock_sorting, 
  CASE WHEN csc_product_currency_items.currency IS NULL THEN "D" ELSE csc_product_currency_items.currency END as currency, 
  products.amount, 
  products.purchase_qty, 
  products.is_invoice, 
  products.ei_order_id, 
  products.ei_status, 
  products.ei_for_user_id 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_mb_vehicle_listing_index AS mb_vehicle_listing_index ON mb_vehicle_listing_index.product_id = products.product_id 
  LEFT JOIN cscart_mb_salvage_cases AS mb_recaon_visibility_case ON mb_recaon_visibility_case.case_id = mb_vehicle_listing_index.case_id 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'ko' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 4) 
  INNER JOIN cscart_tag_links ON cscart_tag_links.object_id = products.product_id 
  AND cscart_tag_links.object_type = 'P' 
  INNER JOIN cscart_tags ON cscart_tag_links.tag_id = cscart_tags.tag_id 
  LEFT JOIN (
    SELECT 
      parent_product_id 
    FROM 
      cscart_products 
    WHERE 
      parent_product_id != 0 
      AND amount > 0 
      AND product_type = 'V' 
    GROUP BY 
      parent_product_id
  ) AS mccd__variation_stocks ON mccd__variation_stocks.parent_product_id = products.parent_product_id 
  LEFT JOIN cscart_csc_product_currency_items as csc_product_currency_items ON csc_product_currency_items.product_id = products.product_id 
  AND csc_product_currency_items.company_id = 0 
WHERE 
  1 
  AND (
    mb_recaon_visibility_case.case_id IS NULL 
    OR mb_recaon_visibility_case.import_source NOT LIKE 'recaon_%' 
    OR mb_vehicle_listing_index.storefront_id = 4
  ) 
  AND (
    mb_recaon_visibility_case.case_id IS NULL 
    OR mb_recaon_visibility_case.selected_flow != 'direct_sale' 
    OR mb_recaon_visibility_case.sale_listing_status != 'hold'
  ) 
  AND companies.status IN ('A', 'S') 
  AND products.company_id IN (1, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 0) 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND (cscart_tags.tag = 'left') 
  AND cscart_tags.status = 'A' 
  AND products.parent_product_id = 0 
  AND products.is_invoice = 'N' 
  AND products.product_type != 'D' 
GROUP BY 
  products.product_id 
ORDER BY 
  instock_sorting DESC, 
  products.timestamp desc, 
  products.product_id ASC 
LIMIT 
  0, 16

Query time 0.00122

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "if(products.product_type = 'V',if(mccd__variation_stocks.parent_product_id is null,0,1),if(products.amount > 0,1,if(products.tracking = 'D',1,0))) desc, products.`timestamp` desc, products.product_id",
      "temporary_table": {
        "table": {
          "table_name": "cscart_tags",
          "access_type": "ref",
          "possible_keys": ["PRIMARY", "tag", "idx_tag_id"],
          "key": "tag",
          "key_length": "767",
          "used_key_parts": ["tag"],
          "ref": ["const"],
          "rows": 1,
          "filtered": 100,
          "index_condition": "cscart_tags.tag = 'left'",
          "attached_condition": "cscart_tags.`status` = 'A'"
        },
        "table": {
          "table_name": "cscart_tag_links",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY",
            "tag_id",
            "ids",
            "idx_tag_id",
            "idx_object_id"
          ],
          "key": "ids",
          "key_length": "6",
          "used_key_parts": ["tag_id", "object_type"],
          "ref": ["devmotorsbay.cscart_tags.tag_id", "const"],
          "rows": 5,
          "filtered": 100,
          "attached_condition": "cscart_tag_links.object_type = 'P'",
          "using_index": true
        },
        "table": {
          "table_name": "products",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY",
            "status",
            "idx_parent_product_id",
            "idx_company_id"
          ],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["devmotorsbay.cscart_tag_links.object_id"],
          "rows": 1,
          "filtered": 98.17363739,
          "attached_condition": "products.parent_product_id = 0 and products.company_id in (1,3,5,6,7,8,10,11,12,13,15,0) and (products.usergroup_ids = '' or find_in_set(0,products.usergroup_ids) or find_in_set(1,products.usergroup_ids)) and products.`status` = 'A' and products.is_invoice = 'N' and products.product_type <> 'D'"
        },
        "table": {
          "table_name": "companies",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["company_id"],
          "ref": ["devmotorsbay.products.company_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "companies.`status` in ('A','S')"
        },
        "table": {
          "table_name": "mb_vehicle_listing_index",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["product_id"],
          "ref": ["devmotorsbay.cscart_tag_links.object_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(mb_vehicle_listing_index.product_id = products.product_id)"
        },
        "table": {
          "table_name": "mb_recaon_visibility_case",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["case_id"],
          "ref": ["devmotorsbay.mb_vehicle_listing_index.case_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond((mb_recaon_visibility_case.case_id is null or mb_recaon_visibility_case.import_source  not like 'recaon_%' or mb_vehicle_listing_index.storefront_id = 4) and (mb_recaon_visibility_case.case_id is null or mb_recaon_visibility_case.selected_flow <> 'direct_sale' or mb_recaon_visibility_case.sale_listing_status <> 'hold')) and trigcond(trigcond(mb_vehicle_listing_index.case_id is not null))"
        },
        "table": {
          "table_name": "prices",
          "access_type": "ref",
          "possible_keys": [
            "usergroup",
            "product_id",
            "lower_limit",
            "usergroup_id"
          ],
          "key": "usergroup",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["devmotorsbay.cscart_tag_links.object_id"],
          "rows": 1,
          "filtered": 99.99243164,
          "attached_condition": "prices.lower_limit = 1 and prices.usergroup_id in (0,0,1)",
          "using_index": true
        },
        "table": {
          "table_name": "products_categories",
          "access_type": "ref",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "pt",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["devmotorsbay.cscart_tag_links.object_id"],
          "rows": 1,
          "filtered": 100
        },
        "table": {
          "table_name": "cscart_categories",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["category_id"],
          "ref": ["devmotorsbay.products_categories.category_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "(cscart_categories.usergroup_ids = '' or find_in_set(0,cscart_categories.usergroup_ids) or find_in_set(1,cscart_categories.usergroup_ids)) and cscart_categories.`status` in ('A','H') and cscart_categories.storefront_id in (0,4)"
        },
        "table": {
          "table_name": "descr1",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "product_id", "idx_product_lang"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["product_id", "lang_code"],
          "ref": ["devmotorsbay.cscart_tag_links.object_id", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(descr1.lang_code = 'ko')"
        },
        "block-nl-join": {
          "table": {
            "table_name": "<derived2>",
            "access_type": "ALL",
            "rows": 22,
            "filtered": 100,
            "attached_condition": "mccd__variation_stocks.parent_product_id = 0"
          },
          "buffer_type": "flat",
          "buffer_size": "75Kb",
          "join_type": "BNL",
          "attached_condition": "trigcond(mccd__variation_stocks.parent_product_id = 0)",
          "materialized": {
            "query_block": {
              "select_id": 2,
              "table": {
                "table_name": "cscart_products",
                "access_type": "range",
                "possible_keys": ["idx_parent_product_id"],
                "key": "idx_parent_product_id",
                "key_length": "4",
                "used_key_parts": ["parent_product_id"],
                "rows": 22,
                "filtered": 100,
                "index_condition": "cscart_products.parent_product_id <> 0",
                "attached_condition": "cscart_products.amount > 0 and cscart_products.product_type = 'V'"
              }
            }
          }
        },
        "table": {
          "table_name": "csc_product_currency_items",
          "access_type": "eq_ref",
          "possible_keys": ["product_id_company_id"],
          "key": "product_id_company_id",
          "key_length": "16",
          "used_key_parts": ["product_id", "company_id"],
          "ref": ["devmotorsbay.cscart_tag_links.object_id", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(csc_product_currency_items.product_id = cscart_tag_links.object_id)"
        }
      }
    }
  }
}