SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b1ce334dd4e11cce93fa2dc7c7afba1153861fd685e80628f7530ccf39f4130' 
  AND token = 'huzCtCTjYb3VR9h/W9Y5glV1mR3XtmCMR9poCBdXJHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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