SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63a9d8b20fcf6f45ce4111633e65b8bb1b46f06951c708d7ff2614b93e93ba68' 
  AND token = '32/6kXwiVPMF89d6KsTJeXR3DIvV+vBljaeRhKqaNl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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