SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aade1af9102f88b61dba0639396d17037df2ff3c42237449fffc5c5cb0da3165' 
  AND token = 'MuTvV6u2GGw3AAJw+/Jj5f4RVU9zPZS16MavIkUw490=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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