I, too, have the same problem. Same macbook specs by the sound of it too.
In my case, it doesn't actually find the result I am looking for in Alfred.
To compound matters:
- it's not consistent for all applications: For example, I can find Android Studio but not Keynote though they are in the same folder.
- It's not consistent all the time - sometimes it will find both but more often than not, Keynote will be missing.
- In all cases, the result is available in Spotlight.
I've tried reindexing and all other suggestions on the Alfred site.
Lastly, *some* results are found - searching for Key returns Keychain and Keyboard Prefs in all cases. It also seems to be limited to a subset of apps. I've observed this with Keynote, Pages, Word, Chrome and Mail. I've never had this problem with TextMate or Android Studio.