MySQL update query not using indexed columns - mysql

Question

I tried the following SQL query to update the table INDEXED_MERCHANT where I have 10000 records in the table. I indexed both "Name" and "A" as Indexed keys to improve the update query performance. By executing the command SHOW CREATE TABLE INDEXED_MERCHANT; I'll get an output result as follows:
INDEXED_MERCHANT | CREATE TABLE `INDEXED_MERCHANT` (
`ID` varchar(50) NOT NULL,
`NAME` varchar(200) DEFAULT NULL,
`ONLINE_STATUS` varchar(10) NOT NULL,
`A` varchar(100) DEFAULT NULL,
`B` varchar(200) DEFAULT NULL,
PRIMARY KEY (`ID`),
KEY `NAME` (`NAME`,`A`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
Here this means both my keys are recognized as indexed keys. When I execute the following command, the "Extra" column result says the query doesn't using the index keys. How should I achieve my goal ?
Executed query : EXPLAIN EXTENDED UPDATE INDEXED_MERCHANT SET ONLINE_STATUS = '0' WHERE NAME = 'A 205' AND A = 'P 205';
Result:
+----+-------------+------------------+-------+---------------+------+---------+-------------+------+----------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | filtered | **Extra** |
+----+-------------+------------------+-------+---------------+------+---------+-------------+------+----------+-------------+
| 1 | SIMPLE | INDEXED_MERCHANT | range | NAME | NAME | 906 | const,const | 1 | 100.00 | **Using where** |
+----+-------------+------------------+-------+---------------+------+---------+-------------+------+----------+-------------+

Answer 1

Your query is hitting "NAME" index as evident in explain output column "key".
Here is the explanation of key and extra columns from mysql documentation
key
The key column indicates the key (index) that MySQL actually decided to use. If MySQL decides to use one of the possible_keys indexes to look up rows, that index is listed as the key value.
Using where
A WHERE clause is used to restrict which rows to match against the next table or send to the client. Unless you specifically intend to fetch or examine all rows from the table, you may have something wrong in your query if the Extra value is not Using where and the table join type is ALL or index. Even if you are using an index for all parts of a WHERE clause, you may see Using where if the column can be NULL.