SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa81e9c8f52829f6cfff8addb4978440d5fdd9952894182eae1fdabfecd6cbd5' 
  AND token = 'dXeaJQsny6K0M3C/17rR9RWfyxRxuLvVDN/68T5dX/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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