SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9536a57669e0a8abb72cc71121092c04d657672a3a9e21267285b7f70242a701' 
  AND token = 'Jbj+8aorOGczbw8kKmgzSrwZLxWqmNT+PRrkJ+FRbqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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