SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e293ad66ab641b6f61c621855aff072793ad95f6da2aa8adb23f99ca86f069ee' 
  AND token = 'xv20d6eZ232to0awZ9kOVcUPP8JkX+oYy/ndu2jSI1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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