You realize that if a unmasked person approaches a masked person and gets anywhere an inch less of 6 feet from them, the masked person will accuse them of assault, don’t you?
I would recommend against it.
Instead, bring an unmasked companion with you and talk to him or her about how neurotic the masked people are as you shop.
My wife and I refuse to wear masks and don’t patronize stores that require it. We’ve turned right around and left Target when told we weren’t welcome without a mask. I’ve been confronted by an old man in a scooter and an older woman in Lowes for not wearing a mask. I just smile and turn around. Never once has it gone past that. I don’t engage, but I’m sad for our society.