SELECT 
  warehouse_id, 
  amount, 
  store_type, 
  position, 
  main_destination_id, 
  pickup_destinations_ids, 
  shipping_destinations_ids, 
  status 
FROM 
  cscart_store_locations AS sl 
  INNER JOIN cscart_warehouses_products_amount AS wpa ON wpa.warehouse_id = sl.store_location_id 
WHERE 
  wpa.product_id = 2786 
ORDER BY 
  sl.position ASC

Query time 0.00060

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "6.80"
    },
    "ordering_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "4.00"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "wpa",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "ref": [
              "const"
            ],
            "rows_examined_per_scan": 4,
            "rows_produced_per_join": 4,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.00",
              "eval_cost": "0.40",
              "prefix_cost": "1.40",
              "data_read_per_join": "64"
            },
            "used_columns": [
              "warehouse_id",
              "product_id",
              "amount"
            ]
          }
        },
        {
          "table": {
            "table_name": "sl",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "store_location_id"
            ],
            "key_length": "3",
            "ref": [
              "dev_yourmart_co_bw.wpa.warehouse_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 4,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.00",
              "eval_cost": "0.40",
              "prefix_cost": "2.80",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "store_location_id",
              "position",
              "status",
              "main_destination_id",
              "pickup_destinations_ids",
              "store_type",
              "shipping_destinations_ids"
            ]
          }
        }
      ]
    }
  }
}