How do I use the YouTube Data API in my iOS app? I get "Access not configured" error on each request

I want to use the YouTube Data API to get the links to thumbnails for a specific YouTube video in my iOS app. I went to Google Developers Console and created a new project.

For that project I then went to "APIs" and removed the default APIs it enables for me and added the YouTube Data API. I then went to credentials, created a Public Key (as I don't need the user to log in or anything, just getting the thumbnail URLs) as iOS, which gave me an API key. I added the Bundle Identifier for my project under Allowed Applications.

Now in my app I tried the following code:

let test = NSURLSession.sharedSession().dataTaskWithURL(NSURL(string: "https://www.googleapis.com/youtube/v3/videos?id=7lCDEYXw3mM&key=*MYKEYHERE*&part=snippet,contentDetails,statistics,status")!, completionHandler: { (data, response, error) -> Void in    let json = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: nil)    println("JSON: \(json)")})

But it prints out the error:

JSON: Optional({    error =     {        code = 403;        errors =         (                        {                domain = usageLimits;                message = "Access Not Configured. Please use Google Developers Console to activate the API for your project.";                reason = accessNotConfigured;            }        );        message = "Access Not Configured. Please use Google Developers Console to activate the API for your project.";    };})

What exactly am I doing wrong?