SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '783ef1914fcfbdc53912a87f8978675dfe3ba36eb7fa4dfb99725f016f66308e' 
  AND token = 'AMQKUU92wPP8DptVYdfPMdWsShk/WPcgrcPJh2AIf1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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