SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edf1edadbfe5ac3d8d3061a2a40b996dde59671788bb0950d704b5c09e943341' 
  AND token = 'f6YtPJYOkizyUlw43WCQDSkXu5DQPXFD0HWPlmelaqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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