A red key-shaped indicator light just below the needle at the maximum
end of the speedometer dial has come on and is staying on. It's not the cruise control 'on' indicator. I've never seen it before. Could it be for the transmission oil level?

 

I believe that has something to so with your security system? Do you have an owners manual?

 

That red key indicates a fault in your Security System. Could be as simple as a FOB battery. Could be the module. I would try the battery first. Make sure your cell phone is not in the same pocket as your FOB.

 

check battery