NOTE: Prepend table prefix to tables in SQL queries listed below if needed.
# login to Admin Console in 2 different browsers (actions below needs to be taken in one of the browsers only)
# go to {nav Configuration > Website > Scheduled Tasks} section
# ensure, that only `delete_expired_sessions` scheduled task is enabled
# go to {nav Tools > Query Database} section
# execute following SQL: `UPDATE UserSessions SET LastAccessed = 0;`
# remember record count in the `UserSessions` table
# switch to command line mode
# execute `php tools/cron.php` command in In-Portal folder
# confirm, that there is now only 1 session in `UserSessions` table