SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '12c128a36f914f3eecf69fd931aa897f715a7174749eb578ea3f8702577c5e74' 
  AND token = 'T1AGVVkP/dBCOXGz9BvwUS0GX18zlWqqgApysmZQfMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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