Add a DB table index to EasySocial

Hello. When I asked server support why does some website pages loads slowly, they say:

You also have many queries running without an index, adding them will greatly reduce the load.

In this topic https://stackideas.com/forums/leader-board-module-and-page-slow-down-website#reply-537053 Sam added a DB table index into `#__social_points_history` and this increased the leaderboard module / leaderboard page query performance.

alter table `#__social_points_history` add index `idx_created` (`created`);

I suppose this pages loads not enough fast:
1. Points Assignment – may be the most slowest page at the moment https://strana-krovi.com/rating
2. All Videos https://strana-krovi.com/videos
3. Dashboard (stream items sort by last modified) https://strana-krovi.com/community
4. All Albums https://strana-krovi.com/photos
5. All members https://strana-krovi.com/badges
6. All badges https://strana-krovi.com/badges (normal load)

Is it possible to add a DB table index by StackIdeas support team?

Or can you teach how to do it? Or may be provide examples of SQL queries? I read few articles about «table index» but it have not a lot examples with Joomla (or EasySocial).

Thanks.