SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eafb5b9bc22d293cf6846a4e283f1825aec324748e1176ed689295b8010954b8' 
  AND token = '4u06+wqTVNl4g+9ZJCdfqNUon7KorPywJ3yQsmpDgEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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