SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61cce31b45ac9e8b4306252fd5b7e9d9ee2e97b81fa177b4b221bb99cacb2a81' 
  AND token = 'cG1CTEHvKmOiKFI9VtY62+SMuBzOt1jFZ+HcuYhNqsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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