SELECT 
  SQL_CALC_FOUND_ROWS cscart_dosiin_posts.post_id 
FROM 
  cscart_dosiin_posts 
  LEFT JOIN cscart_dosiin_post_categories ON cscart_dosiin_post_categories.post_id = cscart_dosiin_posts.post_id 
  LEFT JOIN cscart_dosiin_categories ON cscart_dosiin_categories.category_id = cscart_dosiin_post_categories.category_id 
  LEFT JOIN cscart_dosiin_post_descriptions ON cscart_dosiin_posts.post_id = cscart_dosiin_post_descriptions.post_id 
  AND cscart_dosiin_post_descriptions.lang_code = 'en' 
WHERE 
  1 = 1 
  AND (
    cscart_dosiin_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_dosiin_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_dosiin_categories.usergroup_ids
    )
  ) 
  AND (
    cscart_dosiin_posts.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_dosiin_posts.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_dosiin_posts.usergroup_ids
    )
  ) 
  AND cscart_dosiin_categories.status IN ('A') 
  AND cscart_dosiin_posts.status IN ('A') 
  AND (
    cscart_dosiin_posts.use_avail_period = 'N' 
    OR (
      cscart_dosiin_posts.use_avail_period = 'Y' 
      AND cscart_dosiin_posts.avail_from_timestamp <= 1739348384 
      AND cscart_dosiin_posts.avail_till_timestamp >= 1739348384
    )
  ) 
  AND cscart_dosiin_post_categories.category_id IN (1) 
GROUP BY 
  cscart_dosiin_posts.post_id 
ORDER BY 
  cscart_dosiin_posts.timestamp desc 
LIMIT 
  0, 3

Query time 0.00298

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "cscart_dosiin_posts.`timestamp` desc",
      "temporary_table": {
        "nested_loop": [
          {
            "table": {
              "table_name": "cscart_dosiin_categories",
              "access_type": "const",
              "possible_keys": ["PRIMARY"],
              "key": "PRIMARY",
              "key_length": "3",
              "used_key_parts": ["category_id"],
              "ref": ["const"],
              "rows": 1,
              "filtered": 100
            }
          },
          {
            "table": {
              "table_name": "cscart_dosiin_posts",
              "access_type": "ALL",
              "possible_keys": ["PRIMARY", "status"],
              "rows": 570,
              "filtered": 81.57894897,
              "attached_condition": "(cscart_dosiin_posts.usergroup_ids = '' or find_in_set(0,cscart_dosiin_posts.usergroup_ids) or find_in_set(1,cscart_dosiin_posts.usergroup_ids)) and cscart_dosiin_posts.`status` = 'A' and (cscart_dosiin_posts.use_avail_period = 'N' or cscart_dosiin_posts.use_avail_period = 'Y' and cscart_dosiin_posts.avail_from_timestamp <= 1739348384 and cscart_dosiin_posts.avail_till_timestamp >= 1739348384)"
            }
          },
          {
            "table": {
              "table_name": "cscart_dosiin_post_categories",
              "access_type": "eq_ref",
              "possible_keys": ["PRIMARY"],
              "key": "PRIMARY",
              "key_length": "6",
              "used_key_parts": ["post_id", "category_id"],
              "ref": ["dev_db.cscart_dosiin_posts.post_id", "const"],
              "rows": 1,
              "filtered": 100,
              "using_index": true
            }
          }
        ]
      }
    }
  }
}