Website is not published but it is generating traffic, all entries in the
access_log were generated by requests from the IP of Plesk.
The traffic was generated during using Preview option. The preview feature is designed to see how the site functions without having this site properly resolved in global DNS system, but it is impossible to load the website from a web server without accessing it over the network, so the traffic which was generated is absolutely legit.
To avoid traffic generation avoid using
Prevew feature or change settings in 'Home' -> 'Tools & Settings' -> 'Website Preview Settings'` to use another host for preview.