One-stop is a term used to describe music that has both the master and publishing rights controlled/represented by one party.
One-stop tracks are desirable in sync because it makes the licensing process very simple and minimises complications.
Even if a track has more than one songwriter, publisher, or master owner, you can make it a one-stop track by having legal agreements in place whereby all individuals involved nominate a single party to control the rights and agree to distribute sync fees accordingly based on ownership percentages.