Improving ASP.NET Session State database performance by reducing block

On a recent project, we encountered significant performance issues with their ASP.NET session state database. We had a combination of both large session state and a large number of concurrent sessions. They were regularly experiencing command timeouts on that database. In my investigation, curiously I found that a DELETE statement was the culprit. I tracked it to the DeleteExpiredSessions stored procedure. Looking at it, it seems tame enough: