2008 Mazda Atenza red key light

I have a Mazda Atenza but of course that doesn’t show in the model area.
I’m wanting to know what a light on the dash is.
It glows red and has a shape of a key with an exclamation mark vertical through the center?
I’m wondering if it’s a security warning light.
I had a flat battery and wondered if it was something to do with that?

Here is an explanation for the light for a different Mazda, but probably applicable.

http://nema.club/2014wsm/service%20highlights/books/n6w09/html/id091400603400.html

Google “Mazda key warning light” for more info. I would charge or replace the battery at the least.

Ed B.