SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1942600f7f6ce120f54d98565153345b15732f34be9a55aef6efc88779d47d2' 
  AND token = 'BPCK15ioMeHhTEtChNQyHeHOXVkt2RQJKApjEU6nloc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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