Please list the players who received the "Most Valuable Player" award in the NBA league after the year of 1990, along with their IDs.
player refers to playerID; "Most Valuable Player" award refers to award = 'Most Valuable Player'; after the year of 1990 refers to year > 1990; ID refers to playerID
SELECT playerID FROM awards_players WHERE year > 1990 AND award = 'Most Valuable Player' AND lgID = 'NBA'