SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d4df8cf31df8f97a6233f2b524f5f82ed410b3b1b4b35d8f53e5c9b8dacc24d' 
  AND token = 'UX6oI5P6WwYg/j7l1DyWwbCvC1NQRlXGXbzbg3QVdhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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