SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '049210cc0110922a9ca85cbd45f6d9802274f847c3789bc4e6943256fb78427c' 
  AND token = 'gEYLAqSwQ9AjNNFO017qFfBlAz8U4EUT5VM9fLUuLL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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