If you have a toddler running around, Little Fingers by Shaun Inman – who created it for his own need – will come in handy.
Little fingers want to explore. Press Shift + Control + Option + Command + L to lock down your Keyboard, Trackpad, Touch Bar, and/or Mouse.
Press it again to unlock.
The source is available on GitHub.
Related: AlphaBaby also comes in handy when having babies/toddlers around 🙂