You may already know this, but you have to take the tension off the steering wheel lock in order to turn the key. The SD won't allow you to turn the key unless you do this. But, once you get into the habit..........it's automatic.

Now, if the lock cylinder is failing, you best get a new one.......post haste. If you get to the point where you cannot turn the key........you are looking at a very expensive repair. To change the lock cylinder takes 20 minutes after you have purchased a new one from the dealer. Don't wait another minute on this.