SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72cab834cbb315bac8e3e269df181be3c7d55ba21b0429711df0cd7af061a54f' 
  AND token = 'SLiKzPGjfjrrMsv7KK5fuuLO+pkvLGhdBVHu+GMpFtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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