SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '339ab1fc4cfbfbb18554adbdf8573ee24e3ce1bd061f994cb771dc74a23a4822' 
  AND token = 'PrhCjHWoREuY5fWBzoyc1kORTZD4Fl+ITBb8bhsKqYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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