SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '366520e2c4db35ae16cca9c07ef5494dfe0b42ebdf43af064b2340a23168442f' 
  AND token = '9ItLnKwi8dUAZS8mT7BRIjDBBjfZmrm3pH6SA6j7nQ4=' 
  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"
    }
  }
}