SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddf8b522122a37555bcce734c84be1bd145ed958a4967f6b86ce81c53f479712' 
  AND token = 'w6kuCfUYvcpJFN+JjCxOgls834WQ++5B3/TJl97SPe8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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