SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '715b515945eeeb490895abc5852d49002c3a863d4c13a8e98e0407469bc3a09f' 
  AND token = 'ANy+UcX6GRJQE+I3vJzqF31K8/COvwyq272l1VhAMjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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