SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4d6cd6dda4cc90cdcf37047c386d296d21084551c48529dd30dffc85b6ed141' 
  AND token = 'N21sKoUyGS3czTESZkiNb72I0Itn88hnG3zcX3Oqoq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}