SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee06457cc826e154d4bb9a42ac2ccf3e50d75ce66a8cbfd12f850c84308eb5f1' 
  AND token = 'sFJKnhR9IWDKKH8gzYc44SIKwG7pQOg4jBKD9AXVM+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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