SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d3d961fff6739f69c2ce20e4cbdb83d25c7e99cc044de2422f2423862b7499f' 
  AND token = 'Ak5m5pnhazah0w6VZ6jypjQCyCuGhOxqrPm34G5qgDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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