SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd75d06be41a20e0c8cdba0f954a14eb71f4846aa0c8f994079f49d75ec27197c' 
  AND token = 'cV+QRta7VjB/KGfGKf8pzZMwxEQDdF3FgAH99PpZyZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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