SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33368ce94879d591230ee073bde67ab3488b816f2bb4b39242316631aa232eeb' 
  AND token = 'bMJBz86HePcwSwOXxrXuMkQLQAKD8wu1Z4hbDtKus7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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