why the query time under long_query_time is logged in slow query log?

MySQL & MariaDB Other MySQL® Questions
1

here is content of my.cnf about slow query info

log_slow_queries = ON
log-slow-queries = /var/lib/mysql/slow-queries.log
long_query_time = 10

and here is my slow query log content

Query_time: 0.000570 Lock_time: 0.000045 Rows_sent: 1 Rows_examined: 460 Rows_affected: 0 Rows_read: 1

Bytes_sent: 1232 Tmp_tables: 0 Tmp_disk_tables: 0 Tmp_table_sizes: 0

SET timestamp=1362638541;
SELECT * FROM toocle_suppliers_cate.regional_s WHERE 1 and cate_id = 1522 limit 1;

Time: 130307 14:42:25

User@Host: xxxx @ [xxxx]

Thread_id: 32449 Schema: toocle_suppliers_trade Last_errno: 0 Killed: 0

Query_time: 0.001856 Lock_time: 0.000050 Rows_sent: 1 Rows_examined: 2626 Rows_affected: 0 Rows_read: 1

Bytes_sent: 1239 Tmp_tables: 0 Tmp_disk_tables: 0 Tmp_table_sizes: 0

and i use percona server 5.5.21-55-log

2

i checked the query carefully ,and find this query do full table scan(due to few records ,only 3K records in this table),so the server log the query