
I mean, Amy is the KEY
to your happiness.
The Big Bang Theory Season 7, Episode 21

I lost that KEY chain years ago.
The Big Bang Theory Season 11, Episode 9

But returning to your KEY conundrum,
you should call a locksmith.
The Big Bang Theory Season 2, Episode 3

"Of a Seat, an old one,
in the original KEY holder.
Money Heist Season 1, Episode 7

And mostly,
and I can't stress how KEY this is...
The Big Bang Theory Season 3, Episode 5