SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ace48fd96baed52ea3c478d815399d719863fb0635501db06e5bc5aeb08e2619' 
  AND token = 'OXeDz0dKGJDeovIJFc9b6L4nx70ewuEzg80nMQOwmb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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