SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04c29cdc2824803bf4dbc0c5f3a03edfddb9ea6cc6cde271b06afcb9c912dcea' 
  AND token = 'G0c/FFJC0ks5AZfSB3N2+z6Ax/6lOQthlamKLNoZMFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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