SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be7fc9e6b1654240c1d657c38d13b800d47634ea64453b0e1bf50a9ff8919fc9' 
  AND token = '8xCLgv5iHmFT4gKd+qJaA9Ryjw8o8QsdyQXXJrF/txw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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