If you need a quick fix you can cancel your pending queries. This can be done at three levels: by cell, canvas or workspace:
Cell: Click on the cell and choose 'Cancel query' from the drop-down menu.
Canvas: Click the Count logo menu in the top left-hand corner of the screen > Data > Cancel all pending queries.
Workspace: From your Count homepage select your database from the 'Connections' menu in the left-hand panel. Under the 'Queries' summary select 'See all'. From here you can select some or all of the pending queries and choose to 'Cancel' them.
Also consider if any other tools are running queries on your database at the same time. This could result in your queries running slowly in Count. Addressing these, or understanding if there are particular times when your database is busy, could help things to run more smoothly in Count.