If I'm looking for a physical place I usually just look at Google maps. "Minneapolis antique bookstores." I'll look at pics, see if the vibe is cool, etc. Relying on Google SEO is a recipe for disaster in my experience because there's no guarantee that the bookstore is even in or near Minneapolis. Other people probably browse the web differently though.

I honestly would not expect an antique bookstore to have a website, unless they let you buy their books online.