SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '943ac58da5f3766a6c3a03711525e7cf79f87b452b9476430705b57e9adbd1da' 
  AND token = 'Yjkttdq8HoHon8z4OK32PCCFizxLMrFjl3WBKMeZw+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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