SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c337a5d2a6c92fbff31d9490cced72967c03d1a24e6c1c91a215b16e4ab18b3d' 
  AND token = 'YdjoH/EfjE7UoZX7TJLQCzHYFhavgYbZI9ZqzpdODWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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