SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1ddf35dbc20432e8722849c9dcb704eabf9f7f19b6c2e73b7ac10569cb5d8262' 
  AND token = 'cQVCxHmwGOCB8JwOuBABT0Q5ta3PqCy6iuSWiilTjnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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