My experience is that the only time a key unlocks the movie only 10 minutes prior to the screening is for previews. Usually the keys are valid for about a week.

My experience is that the only time a key unlocks the movie only 10 minutes prior to the screening is for previews. Usually the keys are valid for about a week. BTW, the screen servers will show when a accepted KDM unlocks a feature and for how long it's valid. I have never seen a KDM that is accepted by the screen server and then "doesn't work".