No, definitely don't close it. Part of your score is based on credit MIX, meaning it is good to have a variety of types of credit. More importantly, have the $5k CL must be having a huge positive effect on your utilization (unless you have 10's of thousands of dollars of available credit from other cards, which I highly doubt is the case based your scores).
Kay will eventually "close" the card due to inactivity, meaning that you won't be able to use it anymore. HOWEVER, it seems that Kay continues to report "closed" accounts as open on your credit reports so that you still get the benefit of having your original CL factored into your utilization percentage. That is a rebuilder's dream--a card that you can't use to get yourself into trouble but one that still reports as open to the credit bureaus!!
