6th Singularity Camelot: Land of Emptiness free quest is the best AP & time-saving location to farm Meteor Horseshoe. You'll get about 4~5x Meteor Horseshoe by spending 220AP.
3rd Singularity Okeanos: Caldera Island free quest is the first location you can farm Meteor Horseshoe.
Here is a list of servants that need Meteoric Horseshoe to perform Ascension and Skill Up.
Note: No Bond CE's here.
5 Star Servants Tier List
Best Servants [★4]
Christmas event [JP 2016 Rerun]
FGO Reroll Tier List
Holy Night Supper
Piece of Year 2030