SELECT 
  cscart_pages.*, 
  cscart_page_descriptions.page 
FROM 
  cscart_pages 
  LEFT JOIN cscart_page_descriptions ON cscart_pages.page_id = cscart_page_descriptions.page_id 
  AND cscart_page_descriptions.lang_code = 'ru' 
WHERE 
  1 
  AND cscart_pages.parent_id IN (7) 
  AND cscart_pages.status IN ('A') 
  AND cscart_pages.page_type IN ('B') 
  AND (
    cscart_pages.usergroup_ids = '' 
    OR FIND_IN_SET(0, cscart_pages.usergroup_ids) 
    OR FIND_IN_SET(1, cscart_pages.usergroup_ids)
  ) 
  AND (
    cscart_pages.use_avail_period = 'N' 
    OR (
      cscart_pages.use_avail_period = 'Y' 
      AND cscart_pages.avail_from_timestamp <= 1776178153 
      AND (
        cscart_pages.avail_till_timestamp >= 1776178153 
        OR cscart_pages.avail_till_timestamp = 0
      )
    )
  ) 
ORDER BY 
  cscart_pages.timestamp desc 
LIMIT 
  0, 3

Query time 0.04674

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "read_sorted_file": {
          "filesort": {
            "sort_key": "cscart_pages.`timestamp` desc",
            "table": {
              "table_name": "cscart_pages",
              "access_type": "range",
              "possible_keys": ["parent_id"],
              "key": "parent_id",
              "key_length": "3",
              "used_key_parts": ["parent_id"],
              "rows": 9,
              "filtered": 100,
              "index_condition": "cscart_pages.parent_id = 7",
              "attached_condition": "cscart_pages.`status` = 'A' and cscart_pages.page_type = 'B' and (cscart_pages.usergroup_ids = '' or find_in_set(0,cscart_pages.usergroup_ids) or find_in_set(1,cscart_pages.usergroup_ids)) and (cscart_pages.use_avail_period = 'N' or cscart_pages.use_avail_period = 'Y' and cscart_pages.avail_from_timestamp <= 1776178153 and (cscart_pages.avail_till_timestamp >= 1776178153 or cscart_pages.avail_till_timestamp = 0))"
            }
          }
        }
      },
      {
        "table": {
          "table_name": "cscart_page_descriptions",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["page_id", "lang_code"],
          "ref": ["cscart.cscart_pages.page_id", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(cscart_page_descriptions.lang_code = 'ru')"
        }
      }
    ]
  }
}