SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '462c00fec55e6ea2d291d17470c00d1a8c50f5b157cc83ee83b1bd237e620fa2' 
  AND token = 'LMqmmVD4FnF3nzX0L8IFUrYg1i2NPNL+/lN4lNayMWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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