SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca61e41e1cec532f431da2f50f009edb4de5ab7676112099a360c0b8d52965a4' 
  AND token = 'Uaxd2cBnnG3ijr8bqpbLIeK+cUa4PYoqSgT6SssQYCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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