This type of token was popular in the 1970s and was an effort by the "Downtown Merchants' Association" to encourage people to shop downtown businesses rather than suburban malls. Their problem was that downtown had parking meters and the mall didn't, so traffic was avoiding their businesses. The idea was that if you purchased something from a business, and asked, they would give you a token that would work in the town meters, effectively making parking free if you were quick enough and/or made enough purchases from participating retailers. These schemes were generally not successful because they required special meters, publicity, and public buy-in. There were many different types of parking tokens used across the country - many didn't say where they were used. Also to answer your question, "Park and Shop" was a slogan rather than a particular business.
John in the Great 208