SELECT 
  product_id 
FROM 
  cscart_product_popularity 
WHERE 
  product_id IN (
    12608, 12607, 12606, 12605, 12604, 12603, 
    12602, 12601, 12600, 12599, 12598, 
    12597, 12595, 12596
  )

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "3.12"
    },
    "table": {
      "table_name": "cscart_product_popularity",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "total"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 14,
      "rows_produced_per_join": 14,
      "filtered": "100.00",
      "using_index": true,
      "cost_info": {
        "read_cost": "1.72",
        "eval_cost": "1.40",
        "prefix_cost": "3.12",
        "data_read_per_join": "448"
      },
      "used_columns": [
        "product_id"
      ],
      "attached_condition": "(`test2_gaseus`.`cscart_product_popularity`.`product_id` in (12608,12607,12606,12605,12604,12603,12602,12601,12600,12599,12598,12597,12595,12596))"
    }
  }
}