SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1268a84a2827d9f12f510f48667dfee1ba01a8d88c3ec22ce32d0a0ef984d6c0' 
  AND token = 'myxO66WS59cpSxjSXyih2zKuWRA61soIQHuqgf018OQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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