SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b3665039e5bfc0ec83afd3688be2ec266aef57335b7318548b2c1837370bedc' 
  AND token = 'dwdKt5bcTaWNKjcxexiqMlhJO1jxzsvSvElMADNKikQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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