SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '856aa07da9a2c9fae824abf7bf7e31691fd9e70a1d1c6b2d23e9c1099e215602' 
  AND token = 'Gl9Dy7kXV4fAjC9abxD64wuDOeNG9OO9N6horYRek3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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