How to list of dashboards or looks that used by specific explore?

You can run a query withe the API leveraging the System Activity History Explore and filter on Explore from the Query view, then select the dashboard/look) attributes (e.g. ID, title, link). There are also system__activity/look and system__activity/dashboard which you could use. 

 

query = sdk.create_query(body=models.WriteQuery(model="system__activity",fields=["dashboard.title","dashboard.id"], view="history", sorts=[], pivots=[],filters={"query.explore": "accidents"},limit=1000,column_limit=14))
run = sdk.run_query(query_id=query.id,result_format="csv")