SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '425e406bf714227e4952f7fe56fdad153397e90f67a560d7fca2e2f16a3ffd1f' 
  AND token = 'YM1lYBoiTsL47iwrFPkPSyvM8GITI1VV+NlNQjlNaUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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