SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a064e2a73c998e88c1c382c6e83d0e926368eb464da1b621d0cedf8f8db0d748' 
  AND token = '5Jjo9lKd83zH8DtMDeoU92AK2OVTe6yQ1yjHA5c5BxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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