SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b648c918fe3fe17bfa93ab2929836cc573ddc60f0ccef00994df14371f8647d' 
  AND token = 'duDT07MZMZBmEUSDwg6OY3xZHW3F5LOxOXN7iJ9j9DU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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