Doesn't this risk exist with all types of food factory?
(I say this while eating a hotdog I just got from 7-11)
I see no flaws in this plan.
Dispose of the box carefully and wash your hands afterwards. The pizza is probably fine, though it's fine to cook it a bit longer for good measure too.
You can (potentially) order from a service with contactless delivery to reduce your risk. For example, Little Caesar's will let you leave instructions to leave it on the porch or whatever.