SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fc47df081117b837bc8e8664222805f50dd006db2d4f3361b3b199894607b74' 
  AND token = 'd/86pr1OA19i3te8Z8QYyr2ycJOgAdz6gv3Nei3CFbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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