SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '15883cdccf828b22264f240eb984050914976c82cac4f8fad00048f1e6f76289' 
  AND token = 'lL4UlYefFhrQaAeBv2bIzG7qlx8ETJSuDNjy+ZALBdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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