SELECT 
  p.product_id 
FROM 
  cscart_products as p 
  LEFT JOIN cscart_products_categories as pc ON p.product_id = pc.product_id 
  LEFT JOIN cscart_categories as c ON c.category_id = pc.category_id 
WHERE 
  1 
  AND pc.category_id IN (234, 235, 236, 237, 238, 240) 
  AND p.status = 'A' 
  AND c.status = 0 
  AND p.parent_product_id = 0

Query time 0.01198

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "pc",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "pt"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["category_id"],
      "rows": 17,
      "filtered": 100,
      "attached_condition": "pc.category_id in (234,235,236,237,238,240)",
      "using_index": true
    },
    "table": {
      "table_name": "c",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY", "p_category_id"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["category_id"],
      "ref": ["kigoonlinecs.pc.category_id"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "c.`status` = 0"
    },
    "table": {
      "table_name": "p",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY", "status", "idx_parent_product_id"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "ref": ["kigoonlinecs.pc.product_id"],
      "rows": 1,
      "filtered": 95.62748718,
      "attached_condition": "p.parent_product_id = 0 and p.`status` = 'A'"
    }
  }
}