Yes you can keep your pasta or noodles warm in the crock pot by keeping some sauce on the noodles or pasta.
Then just turn the crock pot or slow cooker down to the low or keep warm setting.
As long as the pasta has something such as sauce or some type of cooking oil covering the pasta or noodles then the slow cooker will keep the pasta warm without burning it.
I use a crock pot to keep my pasta warm after cooking the pasta first in the pot on the stove then put the noodles into the crock pot with some sauce on the pasta and then serve the pasta out of the crock pot while keeping it on the warm setting.
The crock pot prevents the noodles or pasta from getting cold and stays warm enough to serve or eat.