SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0379aa400a3839d251bf4658d75b94ea6e57070fb5bf2d252c50b98c56d1d93a' 
  AND token = 'I4ZFO02jTxkjsqIfUq9omAf5yu7dOCYDZJDAUNiYYBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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