How to restore network keys from SQL?

I think Redis is just upholding the current status of Network keys to be able to communicate with all end-nodes. What kinds of items do I need to insert into Redis’ memory database to be able to restore communication between such an end-device that cannot reset itself and cannot do a new JOIN?

I see there are things in the Application server SQL database in the “device_keys” table. Do I need anything else than nwk_key and join_nonce in order to be able to communicate again with such a device that is still using the keys from a very old JOIN (1 month old)? and how do I exactly inject these values into the Redis store?