SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faadfbdf2cab996a9cfc9c6ae5c1ab2ef16bbb7a147b464de6e4cad69de0f4bc' 
  AND token = 'XQvMNorNR3xZ+wXpsW4LhGwtTTmDzAsEhUe3VnRSCB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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