I believe you need not worry. Should you ever hear about the case again, a simple motion to dismiss it because of years of inactivity would be a likely winner once you are served with process. I believe if I remember right that Ill. Sup. Ct. Rule 105 addresses this kind of measure.
Good luck.....and relax.
It is unlikely the case is actually still open. It should have been dismissed for want of prosecution. You are best to leave sleeping dogs lie. Check the records occasionally if you like. If judgment is ever entered against you, you have a very good argument to quash the summons and vacate the judgment.
I agree with the other answers. You (or someone on your behalf) can always pull the physical court file and verify this, but it sounds like the risk that you have a judgment against is nominal. Good Luck