There isn't an end to the game.
It would also be a little hard to implement a console that can be accessed later in the game.
I've also been getting this issue. I think it's something to do with your character not being able to load but I haven't looked at the crash logs so don't take that as fact.
This 'bug' was way more prominent on my second save, it would happen almost every time I sprinted.
On my first save, however, this crash didn't happen in my first 2-3 hours of gameplay.
Another one of those stubborn bugs.
these are some ways to get keys that I know of:
1. The Keymaster. He can be found in the castle dungeon(east of spawn, near the ravine). He spawns as one of the possible NPCs that spawn when entering the dungeon. He can also be found in the 'regular' dungeon South of spawn.
2. They might drop as rewards for defeating some enemies in dungeons(not sure if this applies to all dungeons or if it is even true).
3. It has a chance of dropping when opening chests(not for the golden chests) or pushing over barrels.
Those are the methods I know of.