SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '113609a5aa02f9f849623c13a6a9aefab1d6e60705b7a9bd13bd4b85d0394bc6' 
  AND token = 'ThOK1SXV/S0lGXKNEb4JbAYZb/dkJ+vv7Om+vhjIWVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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