SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eeb2766b7bdf43c27bd1b3e718e9688015ecf9296866daf9d95017ba4da6d4a8' 
  AND token = '08lMkYCrIqiVVME/ZVjxGxE+0dpy/30i8BysyCTwQJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}