SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57157de3038fca057d290ac5b532da563ec654ef291ac8b1d417ab93315a7219' 
  AND token = 'FFFbvyEJdUpHk9ots8DhoemRVLAuDziglZLQG8+uApU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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