You can get it cleaned if you want to...but you'll probably have to pay something in the range of US$100-150. Basically a full CLA on the lens. (The lens will have to be disassembled completely, so there's no reason not to do the full CLA as the real work is in taking the lens apart and putting it back together...the actual cleaning and adjusting is pretty minor stuff if the lens is working correctly.)

But in reality, you probably won't see the difference in the quality of the images. You can shoot a test roll to see if the images look good to you; if they do, then don't bother having it cleaned. If you get the CLA, you'll find new dust in the lens in another few months anyhow. Because of the way 35mm lenses work, dust is basically sucked into the lens during focusing. Unless a lens is completely sealed (a rare thing indeed as it's hard to make a lens work well if it's sealed), you will get dust inside. But it takes a lot of dust inside of a lens before you can detect the effect even with instruments; with the naked eye it takes even more.

I'd just use the lens. I'm betting that you won't find any visual degradation due to the dust.