Caching and Session on Wrong Servers

I have my cache set to memcached and my sessions set to redis.

Cache prefix is laravel_cache and session cookie is set to laravel_session

When I log into the redis-cli and look at my keys ... I see a key for laravel_cache and nothing for sessions at all.

But when I flush all and then try and load a page I am logged out so it seems that the session is in there somewhere. Perhaps I'm misunderstanding, I don't get why I have a laravel_cache key in redis.

Furthermore, I need to be able to determine if a given user is logged in from an external API call, where would I be able to configure the session to use namespacing to check if a given user is logged in?