SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2934e4f1fe625025609a3f4ca892e66995d9d6e71194b792f0225315f16afe85' 
  AND token = 'qNgLD9AF/h72zYys4Gv1Bc7rBqkoU1jT2W9hsOwzPLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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