Villain is calling station, do I give him a set?

PokerStars No-Limit Hold'em, $1.00 BB (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

UTG ($98.50)
Hero ($105.65)
Button ($104.70)
SB ($119)
BB ($8.10)

Preflop: Hero is MP with K, K.
1 fold, Hero raises to $4, Button calls $4, 2 folds.

Flop: ($9.50) 5, 2, 7 (2 players)
Hero bets $7, Button calls $7.

Turn: ($23.50) 4 (2 players)
Hero checks, Button bets $8, Hero raises to $19, Button calls $11.

River: ($61.50) 9 (2 players)
Hero bets $35, Button raises to $74.7, Hero ???