SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '248999289fc77c8337d6963718427cb449a027cabba79205c4048542c17c5465' 
  AND token = '20Fc02Y4XMFb7gdMBjWZR7ZpmqfNb9GfbmGOdWBAwAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}