Can high level Eldritch blast be used with War Caster?

The final test of the Warcaster Feat is the following

The spell must have a casting time of 1 action and must target only one creature. (PHB 170)

The question I have is whether a spell like Eldritch Blast at character level 5+ qualifies if all of the instances are directed at a single target.

Basically, is the must a restriction on the targeting of the spell, or the selection of the spell itself?