SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ca92ad6c716c3799000c3f4a4a0d38583d9c3e1f38d0353ab4935fc0545b793' 
  AND token = 'VFyuHzbKOgUPXYU5NZhK8wAMwc+LZkXIcAmlDgNrmOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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