SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23f6c8984232f847ed2bbcc3065740a20697ec98dd8b10f42954f56dd6a95fe1' 
  AND token = 'zsBkQ+xjuAKuLt6gbTZGxntJiATe6lMShlLYQO0iMUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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