Too many rows being read

[preston]

I've researched this as much as I know how and haven't come up with a solution. When I run this query it is scanning too many rows. Can someone explain why? The record that gets returned would be the 79th record found based on the parameters in the query. Why is it having to read over 1,000,000 rows?

I've included the "explain" on the query and the actual result.

Thanks.

mysql> explain select sql_no_cache id,date from inquiry use index(merchant_id, date) where date >= '2006-03-22
09:00:00' and merchant_id = 848 limit 1;
+----+-------------+---------+------+------------------+-------------+---------+-------+---------+------------
-+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra
|
+----+-------------+---------+------+------------------+-------------+---------+-------+---------+------------
-+
| 1 | SIMPLE | inquiry | ref | MERCHANT_ID,DATE | MERCHANT_ID | 4 | const | 1066484 | Using where
|
+----+-------------+---------+------+------------------+-------------+---------+-------+---------+------------
-+
1 row in set (0.08 sec)

mysql> select sql_no_cache id,date from inquiry use index(merchant_id, date) where date >= '2006-03-22 09:00:0
0' and merchant_id = 848 limit 1;
+---------+---------------------+
| id | date |
+---------+---------------------+
| 5580925 | 2006-03-22 09:00:06 |
+---------+---------------------+
1 row in set (10.61 sec)