I have a bag of flour in my pantry that expired 3 years ago, but it looks and smells perfectly fine. Is it still safe to eat?  EDIT: To clarify, today is July 3rd, 2018, and the flour best before date is "2015 SE 04"  Question is different from other existing questions on the topic because the duration of time passed is more extreme (other questions describe a few months). 
Update: Now that the OP added a photo of the inside, I think Cos Callis was right, and it's Guava, it definitely doesn't look like an apple from the inside.    It looks very much like a Pond Apple:  The form of the leaves and the stalk/stem(?) looks also very similar.     