SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ace6319ff211823ccd6eb64f88c300d0aedce755366f8d8bfa7390902b2010db' 
  AND token = 'HP+Pk+kK6Xv/wOAnehQ4ycgIpFkGSxEBA//5F7KyshQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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