SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    13101, 12498, 12496, 12510, 12519, 12516, 
    12530, 12526, 12531, 12509, 12517, 
    12523, 12532, 12525, 12515, 12529, 
    12503, 13100, 12507, 12522
  )

Query time 0.00114

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": 20,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (13101,12498,12496,12510,12519,12516,12530,12526,12531,12509,12517,12523,12532,12525,12515,12529,12503,13100,12507,12522)"
    }
  }
}