SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86ec25b3aca29779cc9ede905c3794d3f4dce224f90d963364148bb1683917f5' 
  AND token = 'RV+NzntPYnrAf1QBhodWM1VUgbjKANdbPY8rb/83bvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}