SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12ed12714315bc69c9ae8a21b799aea6ca8fcf499534264d0bb01d83a188ffc9' 
  AND token = 'UCBt0J8yT0N7gelGEjGHvblajdutlqq6TxjoHLHAlWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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