I had a brief look at the list of plugins you have installed, and I noticed you have at least 3 different backup/migration plugins, and at least 2 different caching plugins. We recommend against using any backup/migration plugin because they use a lot of server power, and using multiple caching plugins also just causes both plugins to start fighting each other.
This article explains more what this limit is about:
You should also see the link to this article in the client area while the suspension is active.
The thing is that the MySQL Overload suspensions are not strictly resources. It’s more that we track when the database server load gets too high, and then look for the accounts responsible for that high load. As such, there is no usage counter, or specific limit that we can show you, because there isn’t really a set limit.
As with most resource limit suspensions, the limits are measuring low-level things that affect server load. It doesn’t care what your website does, what software is uses and what functionality those have. So it’s generally very difficult to link resource limits to website functionality.
Sometimes we know from experience that certain features cause high load (chat scripts generate high EP usage, backups generate high IO usage), but only when analyzing many suspensions we can sometimes find a common cause. And MySQL overload suspensions are pretty rare.