SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cd9ba507684c4c6e94bc7d1f739d70a0b25c7920f5d9f7b0ba1f9fcdee9ed89' 
  AND token = 'qIIwIZpLjVH5QgnhC8+QM3F34eCPS6AQFG+6qU3B3KE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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