SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '062432ebad95a95e11d8ff7bdb18e52d90c1d474a639208d32431290644734bd' 
  AND token = 'bbWzixaEFyBEC0HZY8kcFltLih2AMRGhR7GKXv5pn8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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