SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed66f8e6c1efa5023d5666cc69990075d8d499cea7ae38fec005574c0025b306' 
  AND token = 'LPqqijQVpGQdgt6C8OOvtVlSLDQRUH4lsAmHyZzIHco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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