Don't lie about it, even if you think it was egpunged, or should have been expunged.

Expungement of criminal records may give you some rights regarding disclosure to some employers.

"Expungement" of FAA records does not grant any legal protections, ie it is not a legal "clean slate" which grants you the right to lie and be legally protected from the consequences.

If you lie and the airlines find out you will be fired, and that will largely blacklist you from 121.

That's just my understanding.