SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5264088c1d6f823a68c5cd6eeb85e10506055de9987414ffa769b6b8aa15a4c7' 
  AND token = '+Sh+UihUlztI59/psTCVIBuPw34G10qo7CVhUMqXH18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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