SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8006e6f15b3e4c214543ce60f17d1f7368f9f9f96816aabff42862a35aea8dcb' 
  AND token = 'ZusRrz2lI4Q5RqDPO1jcHGfWQ0Ko5huKli0wnK5eGhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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