SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a661678325869b1a6fa011c42603794cf953ded429e85ddf04e2f28fced3b4a' 
  AND token = 'a6L8JcqguAHCeN4adZTqxYHirpfT1x0hUJ7xWkd1wms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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