SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57bd738f8837602089bc68d4e80650e7769b8c2106d922b765f91551c60cb23f' 
  AND token = 'KzSzRt3RZKbKAs2ygoF91ec0E4YK0BueFeX5XQBpewI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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