SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a05ea1536d2e2de81881a0a35c262024cf254b15645b834a49f640b05d03ba65' 
  AND token = '1hFk5Lh6DB6ZyBefBekODd91XNuXliz6idtTESKDi80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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