The endpoint you’d be looking for would be:
https://api.twitch.tv/kraken/search/channels
You’d need to use the following query param query=* this wildcard should retrieve all channels but something to note is the maximum you can return is 100 at a time, you’d need to page through the results till there is no more and store them. Apparently there is 109894370 channels right now so it might take you awhile to page through so many of them. Though you could stop once you start receiving channels with 0 followers because by default they are sorted by follower counts. Assuming that is the important information you’d like.
Subscribers is privileged information so you can’t get that for all channels, not without requesting access tokens from every account on twitch 
EDIT: The documentation (Search Channels) has the incorrect default limit! The default is really 10 not 25. you can increase the amount of results up to 100 through the limit query param. Just thought I’d mention it since it might come up! Haha. Just found out the offset query param for the endpoint has a limit of 999 so if you wanted to collect ALL channels… well you’d need to not use * but rather iterate through all numbers and letters sequentially to get the results numbers down. Your original question though would still be able to be done, through the wild card search.