incorrect Estimated Number of Rows vs Actual number of rows
If you include cd_key in your index, it won’t have to do those lookups and the estimates will have less of an impact. Otherwise, correcting that estimate is going to cause it to do a Clustered Index Scan, which could also be slow. cd_camp is already in there as it’s part of the clustered index key.

But really, the index you want here is:

CREATE CLUSTERED INDEX ixYearCamp ON campdiv (cd_campyr, cd_camp) include (cd_key);