参考：fiddle

SELECT
  case 
      when DURATION_IN_MS BETWEEN 115000 AND 120000 THEN '115000-120000'
      when DURATION_IN_MS BETWEEN 120001 AND 125000 THEN '120001-125000'
      else 'OTHERS'
  END AS grp, 
  COUNT(*) AS cnt
from tab1
GROUP BY grp

就像ysth在评论中说的，把范围分开。
case语句将类别定义为grp，我们将GROUP BY this和count(*)的数量定义为每组。