Top Pair, underplayed???

[barabe]

Poker Stars - No Limit Hold'em Cash Game - $0.05/$0.10 Blinds - 4 Players - (LegoPoker Hand History Converter)

SB: $8.80
Hero (BB): $9.85
UTG: $5.35
BTN: $13.45

Preflop: Hero is dealt A[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/spade.gif[/img] (4 Players)
UTG folds, BTN calls $0.10, SB calls $0.05, <font color="red">Hero raises to $0.40</font>, BTN calls $0.30, SB folds

Flop: ($0.90) 8[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">Hero bets $0.60</font>, BTN calls $0.60

Turn: ($2.10) 3[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">Hero bets $1.00</font>, BTN calls $1.00

River: ($4.10) 3[img]/images/graemlins/heart.gif[/img] (2 Players)
Hero checks, BTN checks

Pot Size: $4.10 ($0.20 Rake)

Should I be trying to extract more value from this top pair?
I am trying to stick to the rule of keeping my pot reasonably small with small hands, and big with big hands not to run into trouble? Would it be better to try to extract more here? Pretty drawy board...