SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '49eab296f9d2e1cccbc83f835be206d30b78a764bdd554df9f7ff21bbe1e7d54' 
  AND token = 'KdRvx476lI9a+QkgiSnnQOooMzDrTiLFFAkN9+eOEYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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