I have a junction table for locks_keys that has an issue with a long primary key column with keys that can open multiple locks

[Pablo_Rios]

I have a question for a base design to track locks and keys. I have a table for locks, a table for keys and a junction table for locks_keys. In the junction table, the locks column can have many locks that can be opened by a single key. I have a composite primary field concatenated with the lock and key values as the primary key. Issue is that the primary key is really long on some records where 1 key can open 5 locks.
Would creating a surrogate locks_keys_autonumber primary field work in place of using the natural keys?