Twitch are working to reduce the delay, but there will always be some delay as by design it gives some time to allow for the stream to come back up just in case it was a brief outage rather than the streamer going offline by choice.
There is no paid service and no 3rd party could do better as any 3rd party source is just getting the data from Twitch themselves anyway.
If you need the fastest possible notifications that a stream has gone offline, you’d have to work with each individual broadcaster you need data for and run an app, or OBS/XSplit plugin on their end that will detect when they stop streaming and send you the data directly.