SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    12582, 12590, 12571, 12632, 12631, 15938, 
    12638, 12599, 12627, 12600, 12639, 
    15800, 12616, 12601, 12628, 12602
  )

Query time 0.00198

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (12582,12590,12571,12632,12631,15938,12638,12599,12627,12600,12639,15800,12616,12601,12628,12602)"
    }
  }
}