Noisy pictures need sharpening, too. It's better to use a noise reducer to minimize grain before you start, but if you can't, or if some noise remains, Smart Sharpen's Advanced options will help you to avoid exacerbating the noise by sharpening it.
Note: If this were an image with a lot of noise in a bright area, such as a sky, you could click on the Highlights tab and follow the same steps to fade the sharpening there.