Can you install Keynote on a Macbook OSX version 10.7.5

Just wondering if anyone would know how i could install a version of Keynote on my Macbook which is version 10.7.5

Everytime i try to buy it off App Store i am told that i cannot complete my purchase as i need version 10.10 or later.

I only bought this Macboook a little over a year ago-surely there must be a way that i can use Keynote.

I have a presentation that i need to do today.

Have tried using Keynote on my iPad but finding it really hard to use. Would prefer just to have a version i can use on my Macbook instead and be able to connect the laptop to an overhead projector for my presentation.

Any advice would be gratefully received.