Keystone XL has nothing to do with current energy prices. It wasn't going to be finished for years anyway.
Biggest reason energy prices are high right now is because shale drillers are actually returning capital to their shareholders rather than increasing production at wild rates.
Just look at what US E&P companies are saying in their public statements, whether it's $FANG, $MTDR, $OVV, etc... It's all about returning $$$ to shareholders, not getting in a dick measuring about how many BBLs you're increasing production by...