SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '988d4ea2b5429aaef68e052308c7c6f6d0bdebfe4239ca1677d5f6c93d0bfe63' 
  AND token = 'KlYwwCfzuXjYqymIfHtws5MrIygiKBmHPUmBdYOhf2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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