SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dd2b4a0ca93638d4099e7e1db4e2cb3f49f3038d95fe4122d241031230ae916' 
  AND token = 'MIWqNbf9r2bUyVabLjXjJLxfXbgxYZriiQ+nJzn279k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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