Get related row based on two MAX Values
This is a clear case to use cte and window functions, please read about them a little. I assume you do not have too much data, so this code is efficient  

;with cte
    as (select Index, cardCode, updateDate, updateTS, unitValue,
        ROW_NUMBER() OVER(PARTITION BY cardCode ORDER BY updateDate DESC, updateTS DESC) as rn
    from YourTable)
    select Index, cardCode, updateDate, updateTS, unitValue
    from cte
    where rn = 1