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SELECT 
  cscart_discussion_posts.*, 
  cscart_discussion_messages.message, 
  cscart_discussion_rating.rating_value 
FROM 
  cscart_discussion_posts 
  LEFT JOIN cscart_discussion_messages ON cscart_discussion_messages.post_id = cscart_discussion_posts.post_id 
  LEFT JOIN cscart_discussion_rating ON cscart_discussion_rating.post_id = cscart_discussion_posts.post_id 
WHERE 
  cscart_discussion_posts.thread_id IN (41906) 
  AND cscart_discussion_posts.status = 'A' 
ORDER BY 
  cscart_discussion_posts.timestamp DESC 
LIMIT 
  0, 10

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "read_sorted_file": {
      "filesort": {
        "sort_key": "cscart_discussion_posts.`timestamp` desc",
        "table": {
          "table_name": "cscart_discussion_posts",
          "access_type": "ref",
          "possible_keys": ["thread_id", "thread_id_2"],
          "key": "thread_id_2",
          "key_length": "6",
          "used_key_parts": ["thread_id", "status"],
          "ref": ["const", "const"],
          "rows": 1,
          "filtered": 100,
          "index_condition": "cscart_discussion_posts.`status` = 'A'",
          "attached_condition": "cscart_discussion_posts.thread_id <=> 41906 and cscart_discussion_posts.`status` <=> 'A'"
        }
      }
    },
    "table": {
      "table_name": "cscart_discussion_messages",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["post_id"],
      "ref": ["cscart_migrate.cscart_discussion_posts.post_id"],
      "rows": 1,
      "filtered": 100
    },
    "table": {
      "table_name": "cscart_discussion_rating",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["post_id"],
      "ref": ["cscart_migrate.cscart_discussion_posts.post_id"],
      "rows": 1,
      "filtered": 100
    }
  }
}

Result

post_id	thread_id	name	timestamp	user_id	ip_address	status	email	message	rating_value
125765	41906	Cody Mueller	1697920620	0	cfb7a592	A	cody@hotelsjh.com	We renovated The Hostel - one of the original buildings at the base of the Jackson Hole Mountain Resort. We used surface mounted conduit to add more lighting in the guest rooms. Our Barn Light fixtures provided an ideal rustic feel in our mountain west setting, along with the industrial feel of the surface mounted conduit. The fixtures look great, are very solid, and were easily customizable to the size and color requirements for our space and design. The original design called for a Wallaby gooseneck fixture near the door, but we then decided to install new high-efficiency heat pump air conditioners in that location. The fixture was easily customizable to a flush mount on the ceiling, making the change painless. We could not be happier with the end result.	5