I was going to say Celtic based on the style of the reverse horse (I assume that is what it is). It could be Greek.
My first thought is that these photos are not focused and the coin is not properly lighted for identification. We need to see the actual relief, not just the contrast between oxydation and cleaned metal.
Yes. To be more specific, what @Victor_Clark is saying, is that your coin is a fake, which was created in modern times. @Victor_Clark is saying, that your coin is pretending to be an ancient Celtic coin. The ancient Celtic coins, often looked similar to ancient Greek coins, such as the Philip II coins.