SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da4e8168a671dd9391b4cf00b7d09bd89a1815026f238797453a2ecf8a3efa91' 
  AND token = 'omjcltqUs2puuP9dHJXxN88ZylRyXlJgoPKHycQQ6OY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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