SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32efd9464642cf1ed4d15b5816e7609b50ee9928e9b185febf98ebd7e4b98352' 
  AND token = '75oTZafitfiKolrpnaHOpvJ2oHsqufPIfoXNc6yfuKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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