To keep your pasta fresh in your crock pot and to keep the pasta from drying out and prevent the pasta from sticking to the inside of the crock pot you can spray the inside of the crock pot with some PAM or other cooking spray.
Or coat the inside of the crock pot with some olive oil.
The olive oil or any cooking spray helps to prevent the pasta from sticking and also helps keep the pasta fresh and prevents it from drying out.
You might also need to add a bit of water to the pasta in the crock pot and keep the crock pot turned down to low.
When the pasta is done cooking in the crock pot be sure to turn the crock pot down to low heat to keep it warm but to avoid it getting too overcooked and dried out.