SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca5b3a1497df1e56b752794c7688f3a413910454aa5f98922d98012891979409' 
  AND token = 'T8PcNYRKUjoOhhwBB/T5XKlexRijSgGp7QvDX8lLkT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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