SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34f6a47ca613812b3b5c862810880691758f8a05f3c2b992d61033c462ed8a97' 
  AND token = 'SIDIKztz8XHQ3U8dfHAkl8zdFkIe+IvV2ahkHSzEXJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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