I think this line is a takeoff from "WarGames," not "Crimson Tide." George says "I'm going to have to ask you to turn your key." Maura say "I'm sorry George I can't do that." George then yells "Turn your key, Maura. Turn your key!"
The line is stolen straight from WarGames! When they said it, the two guys were in a missle complex, and one even pointed a gun at the other, ordering him to turn his key! Now it's been awhile since I've seen either movie, but I remember clearly that dialogue from WarGames.