SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92ce660af386c70f1fed7e35b30b3c961f5302958d863d85848bc51fb4475a68' 
  AND token = 'QSyVAMkgg/xmyUKNO4WDmaiS6qKzLaP5rKpHnC9bJP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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