SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '69b280380e529af5f7b5587dc3a83b84bdb640d00da9236de40910f5fb349a3e' 
  AND token = 'TP6GNiAtW6him1k+v/Mk7bZmESznvZC/zZIQrnGWov0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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