SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c552f8397b718f6ab0f17281534e4a8cea31b25d02054ab39c8f447105926548' 
  AND token = 'IqcPOyhxa/Dx0rJI6kDj2F6v2mIEo7dQHw4dKgHlLfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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