Had some fun yesterday.

Key was getting harder to turn in the ignition and often didn't want to come out easily.

Finally bit the bullet yesterday, pulled the barrel right out, cleaned out by spraying and flooding with lubricant spray - lots of grey lubricant dribbled out - and back it went.
Working well.

If yours is getting difficult, don't keep forcing it, just makes it worse. A new barrel is expensive, comes with two keys but the car needs to be recoded by a dealer for the new keys to work. Then of course you need to keep the old key if you want to open the door manually.

Also discovered every time I bent down near the Lancer with the keys in my pocket, it would trigger the lock/unlock. Battery now removed.