There are a couple of things to note. First, Laravel doesn't store cache records to Redis with that exact key. It'll add a prefix to avoid key collisions. That prefix is defined in the config files.
Secondly, cache records are stored in their own Redis database by default. Check the Redis section of the database.php configuration file and look for the REDIS_CACHE_DB entry. If you connect to Redis via redis-cli, you first have to switch to that DB before you see the keys:
redis-cli
> auth [your password]
> select 1
> keys *
If the cache is in DB index 1, you should see your cache keys there.