Expiration of storedhttpsessions

We are using the HTTP Session failover feature, as described here: https://help.hybris.com/6.3.0/hcd/5da5660b2a3f4263ac3095d900d07f88.html

BTW, other than documented, we cannot use 'JSESSIONID' as cookie name. But: The real problem is, that we do not monitor any expiration of storedhttpsession objects from persistent storage, and are regularly running out of disk space on the DB with this feature enabled.

Question: How to enable the deletion of expired sessions from the underlying table?