ConnectedApplication entity can be to query Salesforce Connected App. Use SOQL on ConnectedApplication entity to query Connected App details.

Sample SOQL:

SELECT Id, Name, OptionsAllowAdminApprovedUsersOnly
FROM ConnectedApplication

For additional columns on the ConnectedApplication entity, please check the following article for reference.
https://developer.salesforce.com/docs/atlas.en-us.object_reference.meta/object_reference/sforce_api_objects_connectedapplication.htm