checking over the logs I am seeing a high number of slowlogs from the sitepress multilingual plugin, nearly 3000 in the past 2 hours. Some examples can be seen here: скрытая ссылка скрытая ссылка
Slow log events are PHP processes that take more than 5 seconds to process. This is significant because PHP processes typically happen almost instantly, so 5 seconds is substantial. We read them from the bottom (where the process starts) to the top (where the process stalled). I’d recommend reaching out to the plugin developer to see if they are aware of this and have a possible solution.