SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f490fe94f33e1d3c6209269d74d24b8e703ed7b4be0c77ab35517fc765097df' 
  AND token = 'UkaNDjIYZ2h4E6yfyye7IUiuFi6DZerw2aVwx3jj+fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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