PolarDB的select，每次都扫描都是大几十万行，怎么处理？

PolarDB的select，每次都扫描都是大几十万行，怎么处理？MySQL [domain_db]> select count() from user_train_list;
+----------+
| count() |
+----------+
| 1074992 |
+----------+
1 row in set (0.163 sec)

MySQL [domain_db]> select count() from user_train_list where traintype = 1;
+----------+
| count() |
+----------+
| 1067965 |
+----------+
1 row in set (0.190 sec)

MySQL [domain_db]> select count() from user_train_list where traintype = 1 and 2 > robTimes;
+----------+
| count() |
+----------+
| 932975 |
+----------+
1 row in set (0.224 sec)

MySQL [domain_db]> select count() from user_train_list where traintype = 1 and arriveTime > 1720421130477;
+----------+
| count() |
+----------+
| 1062140 |
+----------+