SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e3a40b4224631e548bc415853cba0df35b80526c5f1eaa7ea2144c854dc4861' 
  AND token = 'EQuTolumEiAExS2N/zv0DN+uiuTPssynrT6UuLXL0gA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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