SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '041683d2a04421ba964dbf1b439e925976907dc64e85aab042f1712c00505f11' 
  AND token = 'OQ6YA5eW6W3vvHk/KwkeQaejgESeJZo1QKKeAGJy440=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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