You can't sacrifice a Clue to activate its own ability and also to activate another ability that requires sacrificing a Clue (or any artifact) as a cost, such as that of Lonis, Cryptozoologist.

The token is named Clue Token and has the artifact subtype Clue. Clue isn't a creature type.

The tokens are normal artifacts. For example, one can be sacrificed to activate the ability of Breya's Apprentice and one can be the target of Break Ties.