Technically it's not possible. A PHP application is stateless, so every request stands on it's own. Only a cookie that's passed back and forth can create state via the session, by for example re-login a user who's id is in the session.
In one of our apps, we have "last_login" and "last_seen" columns in the user table, both containing a timestamp. The first is updated at the actual login, the second at each Auth::check() call.
Using something like that you could for example define "logged-in" as last_seen set within the last 15 minutes.