SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    447, 368, 432, 433, 434, 435, 436, 437, 
    438, 439, 440, 441, 442, 443, 444, 445, 
    446, 369, 417, 418, 419, 420, 421, 422, 
    423, 424, 425, 426, 427, 428, 429, 430, 
    431, 367, 402, 403, 404, 405, 406, 407, 
    408, 409, 410, 411, 412, 413, 414, 415, 
    416
  ) 
  AND cscart_product_descriptions.lang_code = 'es'

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.08599183,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_descriptions",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "product_id"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["product_id", "lang_code"],
          "loops": 1,
          "rows": 49,
          "cost": 0.08599183,
          "filtered": 100,
          "attached_condition": "cscart_product_descriptions.product_id in (447,368,432,433,434,435,436,437,438,439,440,441,442,443,444,445,446,369,417,418,419,420,421,422,423,424,425,426,427,428,429,430,431,367,402,403,404,405,406,407,408,409,410,411,412,413,414,415,416) and cscart_product_descriptions.lang_code = 'es'"
        }
      }
    ]
  }
}