NL 25: pair + FD, riverbluff?

[M.P.Rator]

PokerStars No-Limit Hold'em, $0.25 BB (5 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

MP ($26)
Button ($2.95)
SB ($14.70)
Hero (BB) ($26.55)
UTG ($14.95)

Preflop: Hero is BB with :qc, :3c
3 folds, SB calls $0.15, Hero checks

Flop: ($0.50) :6c, :qd, :kc (2 players)
SB bets $0.50, Hero raises to $1.50, SB calls $1

Turn: ($3.50) :4s (2 players)
SB checks, Hero bets $2.50, SB calls $2.50

River: ($8.50) :ad (2 players)
SB checks, Hero checks

Total pot: $8.50 | Rake: $0.40

villain: relativ unknown, richtung donk/station

river bluffen? flop nur callen?