Any USB flash drive will work with USB 2.0. It depends on wich USB you buy. The fastest you can get with USB 2.0 is 480mbps that is the same as 35mb/s~. So try looking for a USB that has a write and read close to that. Getting an USB 3.0 is going to work aswell and can even be held back by the 2.0 port.
Nonsense USB 2.0 is all about transfer speed. In USB3.0 they have additional connectors which remain unconnected when USB2.0 device is connected to the USB3.0 host (or if USB3.0 device is connected to USB2.0 host). If the electronics doesn’t detect additional data signals, it act according to USB2.0 standard. It just contains more connectors and there is more wires in the cable. But USB only transfers data there are some exeptions like VR for example will only work with 3.0. So there would be no problem.