SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93ab139ab41603571e59aecd05d7d6c690e95e725f83a198f568b885f4e931bc' 
  AND token = 'wAXmjMg47hlTe4CJQ4cQrWjq8tpwLkmdCyVgsv/3L8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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