SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2448065f8c8277d2e394a76c9d544e875595773c4221b828b6b9a1adb50c1df5' 
  AND token = 'sismJjdNOrHcqSE8Gtj4qfQT/tJFXuLq/GOMm+epmwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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