SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a054a04b2cc37c02cba8d87f62173abf793666cfbb0bca7ed9eb1c5d45a967a4' 
  AND token = 'wPnFmKTikwkkGvvBTOkz6Npf+KlVvLQ+EqfDjKwGjsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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