Villain is 15/13/3 over 113 hands. His fold bb to steal is 90. He has donked 2 of 2 times.

I don't give the donk alot of respect but decide to float instead of raise. Call or fold the river? Thx.

Full Tilt No-Limit Hold'em, $0.10 BB (6 handed) - Full Tilt Converter Tool from FlopTurnRiver.com
BB ($12.36)
Hero (UTG) ($24.54)
MP ($7.24)
CO ($10.63)
Button ($43.77)
SB ($12.58)

Preflop: Hero is UTG with Q, K
Hero bets $0.30, 3 folds, SB calls $0.25, 1 fold

Flop: ($0.70) 10, 4, 5 (2 players)
SB bets $0.40, Hero calls $0.40

Turn: ($1.50) Q (2 players)
SB bets $0.90, Hero calls $0.90

River: ($3.30) 7 (2 players)
SB bets $2.20, Hero ?