SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ae3fe5ab21d55cc97d568012e668dc3f2615dc981c439ecd696d17b3a4109e6' 
  AND token = 'h5fuu81uD5A1jOUb6SfqUqZbt1Jf/ruTspW8J6sK8ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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