SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afb21e8d17d770ce8001e76fcd98a0458adcd12ff15617d8aae7a8d60835ce49' 
  AND token = 'pjnOOHXJ80DJve33DMy/96Gj8OgKjjSye8WrunX4ZCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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