SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    5955, 5956, 6082, 6083, 6084, 6085, 5753, 
    5754, 5756, 5755, 5954, 5953
  )

Query time 0.00058

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": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (5955,5956,6082,6083,6084,6085,5753,5754,5756,5755,5954,5953)"
    }
  }
}