SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60ebd865f03bd554952c930001e8d4b6a8ca055276ae2a976082081723563b76' 
  AND token = 'klfJ3oohUalC+SdEAgATMXTHcw8F2JpYmAxRjT+o1SE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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