SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b33c2d28c8bb5142d5a08024751742e2b17f7a90396c5a15aa1d2951977d6e74' 
  AND token = '4oZqhskkkJ6qWdlZqOg6W+7xwzrtWqf5TSvgcAsUoWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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