SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30ced48f28d0304b059919547461bcfb855a3840f1231169cbb6b8d61e4ebc8d' 
  AND token = 'KkGut8JLgywzSxI23BuvVvz5eECk/Mp9T1m11yKSkGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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