SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '13d21d01056117a088a45ee4099530ae302c973a343ff7b688c27753500eae9e' 
  AND token = '8Eq3ZGdqTw7/zpKITV8NhYMubCSywZID7x9Kbw/4UBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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