SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1793b88b9eab505927522da045d112db0a2e2237277ce828e5fe185ad5f48c60' 
  AND token = 's/LkrYec7PJ44MAZM+AKkxkcDazEnUqQ8ErLyw/9M9E=' 
  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"
    }
  }
}