SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '445309f5d7f4e2b9ed15326ce45cba33f8bbfb10ad9b1119bf80246f4e738c56' 
  AND token = '8FY0xTTGD7szBTXqWRUKob4vqDJca8boPoXjVp6vWzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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