This is a common problem. It comes from the anti theft device built into the steering wheel; which locks the wheel if it is turned when the key is not in the ignition. The way to prevent this from ever happening again is to develop the discipline and presence of mind to never move the wheel when the key is not turned on.
But for now; the way you can avoid calling the locksmith is to jack the front wheels up high enough to get them both off the ground at the same time. A tow truck driver will do this for you; if you have towing insurance (or even if you have to pay). Once the wheels are off the ground, the pressure will be taken off the steering wheel; and it should then become easier to move it to the one spot where the key will become free to turn.