SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9620c8f528256db96d7cd9c08e7618b7971a7485e52407a8d1d2c604dae59f8' 
  AND token = 'oxnjV1Bsjg9N5Y/GITDzZIvFxGhzo9wcdPjUKGbXB3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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