SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e16982dc3361e42c9a9d8140ed8c65d2323211aeb3b82e03a0e64a10ff2731f' 
  AND token = 'dYTDvjXLOOeHAqu0DBJ1+aujXrpfDFm0ZZYGXVW8q/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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