SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c3ad1cd797612dac8d21bbdc494f4bab7d0cb1a95498e52dcdd87cd7755063' 
  AND token = 'ahc4ikwBYr6ifIGRYJBQSaeDN/K8lnWQ5fufJn6QXDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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