SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86566230946c45d8e182c85abe2e78c833bb2fd0ef5842708d968fbe036a6c26' 
  AND token = 'NzYHuzJk0WrbZtXWRnYB/yeRjnBpx+t7zcWxcPgZwWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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