Download kid-key-lock, to disable keyboard and mouse
With Kid-Key-Lock you can prevent toddlers from accidentally pressing unwanted buttons on your keyboard and mouse, but you can also disable your keyboard and mouse in order to clean them.
Kid-Key-Lock seats on tray for easy access and it can be set up also with a shortcut key. Note that It is not totally reliable, sometimes, after persisting pressure, keyboard keys escape their lock.
A similar program, toddler keys, is equally unreliable. Here is then what I do: pressing the WinKey + L I log off and the keyboard is instantly locked, without using any other software, but the Windows native abilities. Just remember your password to log in again!
Note also, that if you are listening to music, it keeps playing while you are logged off (although you can not change the volume of course).