Literally just don't open the hatch. The real world counter to the typical cheapo meme drones is putting covers over your hatches because these tanks are designed for you to get out and look around sometimes. Any mech with the typical sort of sensors and cameras you normally see can just leave the door closed.

If you want it actually directly approached as a future warfare idea, watch short peace. Anti-tank drones used with distraction tactics against a mech with lasers set to anti-drone. It's the best that's been done with the concept.