Many shops in Beijing are recruiting hourly workers. . I saw them recruiting hourly workers at Longde Square in Tiantongyuan the other day, not necessarily students. I also saw McDonald's recruiting in Datun a while ago. Go to their official website and have a look. Although it may not be published, after all, there are so many stores in Beijing. Generally, this kind of thing is handled by each store.
or, where do you live? You can just search the phone numbers of KFC and McDonald's stores near you and call them all to ask. If it's near, you can just go to the store and ask the manager.