SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12c6a028a687de079a951f165b2d811a30a4887fe167977aa586e31ce070c364' 
  AND token = 'APnjwsZEYzcQTgb4fQBMQHglp9nHdBTCJtTWux7A+OI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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