SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d15c245be3ecc4daf3d1dbbbde06588247b6ba5efb9d1027d994d9d89046e81' 
  AND token = 'SonMI4CjehCopx8TgfVAzxq4/wwH1lkUu/DgnSRxOx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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