SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9609ab100ed411e867c52c40a254142329701a85bc4f834af02fd26900180638' 
  AND token = 'PyQnvXstpxY+fbg3udKl7LRE7HXiY03nI2mfMeo5eSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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