About iPhone 5 Unlocked and Locked?

My dad just buy me an iPhone 5 which purcashed from Singapore, and now i use Indonesian sim-card and it's worked. I go to a site and checked my iphone it's unlocked or not, but the result is locked. ( from iphoneox.co*, dev.mk ) not sure is true or not.
the question, if my iphone is locked, then why i can have a Indonesia Signal on SimCard?
it's mean unlocked or not?

Singapur iphones 5 are unlocked look http://m.olx.com.sg/item/show/439874837

Msg this guy from ebay… He can help you http://www.ebay.com/...0984052698