Woke up to find that none of the keys on my laptop worked.

I solved this by turning off the laptop, unplugging power from both wall and laptop, taking out the battery and then doing everything in reverse - putting battery back in, etc. By some miracle the keyboard worked.

The question is: is there a way to unlock a locked keyboard without doing all the above?

I think my cat walked across the keyboard in the night and probably "pawed" in some combination of keys that locked it up.

Please do not tell me to close lid of laptop when going to bed - that's a given!

What I'm looking for is like a function key and something to push that is the magic "unlock." Am hoping for that info if it exists.

Check to see if it is a Function Key. "Fn" and another key. The will have symbols on them.

Secondly, I would suggest locking your laptop if you want to leave it running overnight. This way if the cat walks on it, it shouldn't do anything to your computer. Also, of course, you could put the laptop in Hibernate to save the work you are doing.