Assuming you have access to the _audit index, you can just literally search for events in the _audit index where the search field has your index name in them.
You will probably also want to do a search for reports and scheduled or saved searches using the appropriate endpoint, then filtering for searches that have the index name. This latter method will only, however, find searches that you have access to see. For instance, they must be at the app or global level, not someone else's personal saved search.
