SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b9a8d149a7f42c5350637a2662dc0a2c7a905bb686bd2c1ffd526108d45b2d8' 
  AND token = 'WOZ6+JO/S1QZW3eOt6/AGZ/pmlFP6qVDZ2Ybv4UvJKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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