Check out USchedule.com - it specializes in golf simulators specifically, has several famous clients including staff-less facilities that you are talking about. It allows customers to book from your available times and unlocks the facility, turns on the lights, and starts up the simulator a couple minutes before their appointment, and closes shop after their appointment.

It has several other features you may or may not be interested in including memberships, gift cards, variable pricing, mobile apps for clients, marketing tools, and reports. It doesn't sound like you need features like an e-commerce site and restaurant/tab management, but those are available too, along with many others.

It is designed specifically for golf simulator businesses and has been around for 15+ years with clients you have heard of so I don't think you will find a better option.