You're facing a couple of immovable objects here.

First, DBI/DBD is fundamentally request-response. There's no facility for asynchronous notifications.

Second, MySQL doesn't have stored procedures. You are, however, free to invest time and effort adding them, but it's not a trivial project.

Third, unless you're able to add a notification layer between the database and clients who are adding data, you're going to have to poll, and efficient polling is going to require either a unique ID field or a timestamp on the table, so that can avoid a full linear scan time you poll.

Bottom line: If the requirements are non-negotiable, walk away from this one.