SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a21ac6c9aa8833ddc87d237a891535b2a180c5697b8054a1c22f59f88436be9' 
  AND token = 'NDbWEbD4MS5Yyj7ARrOmhUcg4BwzS/LlYrwN6RgrsCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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