SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38128864e9857adb4cd3ed850af42efd3444b64f184f6cb355cc5890af1770fc' 
  AND token = 'Xy3xMrV285cwCAebuAQrdaX8PYqjcaD4+eKvPakd520=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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