Then use Redis (perhaps via cl-redis), if that's what you're comfortable with and it meets your use requirements. Most of the major NoSQL databases have CL bindings. Most of them are also easy to use. It really depends on what your specific data persistence needs are...? All of the db engines have different strengths and weaknesses.
There's cl-mongo (MongoDB), cl-tc (Tokyo Cabinet), de.setf.cassandra (Cassandra), chillax and clouchdb (CouchDB), etc. etc. [Some are more complete and performant than others, but you can find a usable CL binding for almost any NoSQL db. Use a search engine and/or ask on IRC or comp.lang.lisp for pointers.]