1.   It felt to her as if they had just unlocked the key to the whole universe, but she had a feeling that was not what he meant.

2.   Has Mayfair unlocked the key to playing consistent golf again?

3.   If scientists can find a cure for the disease, they may unlock keys to the aging process that affects everyone.

4.   This wormhole unlocks a key to dimensions that look similar to those on Earth but have a few things slightly askew.