When data travels through Fiber Optic cable it travels pretty darn fast to get that data from one location to another and such as when I post this answer the data I enter here will travel within less than a second from my location to the data center where the server this website is hosted on is.
So that means that data travels through Fiber Optic cable just about as fast as light travels depending on how much data you are sending through the Fiber Optic Cable.
The data on this answer will travel at the speed of light through Fiber Optic cable because Fiber Optics use light to transfer and decode data.
Most data through Fiber Optic cables though travels at a speed of 200,000 kilometers per second which is pretty fast.