2 minutes and 40 seconds!

This is 2nd verse of Jingle bells sung by Jim Reeves.

Now the ground is white
So, go it while you're young,
Take the girls tonight
And sing this sleighing song;
Just get a bob-tailed bay
[two-forty as his speed]
Hitch him to an open sleigh
And crack! you'll take the lead.

In the bracketed wording above, what does two-forty mean? Is it 240 miles for a horse speed?

The reference in the final verse is to a bob-tail bay with two-forty as his speed. A mile in two minutes and forty seconds, especially pulling a sleigh down a country lane, is a brisk speed. This song was written at a time when the average person would have recognized this as a horse from the harness racing world. Racing Standardbreds hitched to cutters (one-horse open sleighs) is still done in some areas for fun.