MongoDB indexed range query slower?

gistfile1.js

> db.ip_blocks.find({start_address: {$lte: 1665637698}, end_address: {$gte: 1665637698}}).explain()
{
	"cursor" : "BasicCursor",
	"nscanned" : 3662284,
	"nscannedObjects" : 3662284,
	"n" : 1,
	"millis" : 2645,
	"indexBounds" : {
		
	}
}

> db.ip_blocks.ensureIndex({start_address: -1, end_address: 1})                                                                              

> db.ip_blocks.find({start_address: {$lte: 1665637698}, end_address: {$gte: 1665637698}}).hint({start_address: -1, end_address: 1}).explain()
{
	"cursor" : "BtreeCursor start_address_-1_end_address_1",
	"nscanned" : 1,
	"nscannedObjects" : 1,
	"n" : 1,
	"millis" : 4336,
	"indexBounds" : {
		"start_address" : [
			[
				1665637698,
				-1.7976931348623157e+308
			]
		],
		"end_address" : [
			[
				1665637698,
				1.7976931348623157e+308
			]
		]
	}
}