SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed36a16bb496cc38e25b5c6a4a566b7a7bec539537b413e2bc01b36fa4014a98' 
  AND token = 'kiL0BtjkvxvoUdUiXv3TOcdCokCrs0LgyWtzMxMqpiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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