SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    14140, 14141, 15747, 15748, 15751, 15752, 
    15753, 15754, 15755, 15756, 16334, 
    16335, 16338, 16339, 16340, 16344, 
    16345, 16348, 16349, 16350
  )

Query time 0.00056

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.03556692,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_products",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "loops": 1,
          "rows": 20,
          "cost": 0.03556692,
          "filtered": 100,
          "attached_condition": "cscart_products.product_id in (14140,14141,15747,15748,15751,15752,15753,15754,15755,15756,16334,16335,16338,16339,16340,16344,16345,16348,16349,16350)"
        }
      }
    ]
  }
}