SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2147a2bf62bb683729d8e6935f04b371855cf87afeb20e6bab566e274753fc7b' 
  AND token = 'wGGzByPCU5TW/uRWzUhc4NvIaW+LC0lHYrMqTY2oG04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}