select * from data where sn='221' and pq='hum' order by id desc limit 4
idsntspqvaluesystemts
41215421 221 hum 26.50 1598614860 Fri 28 08 2020 13:41:00
41215416 221 hum 25.90 1598614800 Fri 28 08 2020 13:40:00
41215409 221 hum 26.30 1598614740 Fri 28 08 2020 13:39:00
41215406 221 hum 26.70 1598614680 Fri 28 08 2020 13:38:00

Mon Jan 18 16:42:50 2021 by walley