key-bearer
/ˈkiːˌbɛːrə/noun
1A person who has the custody or control of a key or set of keys, especially in a ceremonial role.
2 Christian Church. A person possessing spiritual authority, as symbolized by keys; specifically (chiefly with the) St Peter as the bearer of the keys of heaven, or the Pope considered as his successor.
Origin
Late 15th century. From key + bearer. Compare key-keeper.