SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f48081473345b167ef856e1744a2b7f6a7301d83fce1213a329f994cd6ebd90f' 
  AND token = 'mAYqZUXkGtu6hvuKs9Ut9ICiQh/hWmrXxgo9lWi+Mvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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