SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee6fd6d7408a8ee394121eaf0662ba2e8845b965efe0a7f9148a90abc3a12914' 
  AND token = 'L4hHdYQz9XdgbIQ0RyMDhLWj71pRO4Mf6euW9RrB25Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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