1: Download USBDeView
https://www.nirsoft.net/utils/usb_devices_view.html
2: Move the Connect Time and Disconnect Time columns near the front so you can see and sort by them easily.
3: Set the options similar to this (optional, but recommended):
4: Sort by Connect Time column by clicking the column header.
5: Take the computer offline. Disable Wifi adapters, and unplug Ethernet.
6: Ensure the computer is set to NOT go to sleep. If Windows is trying to install updates, install them and reboot so it is fresh.
7: Plug in USB Device(s) you want to test.
8: Take a picture of the screen so you have a reference of what it looks like now.
9: Wait some time (days or weeks) and check to see if any unauthorized devices have shown up in the list, most likely a fake keyboard.