SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8be3a52408cf93b4565ac53846ae8b47230c71b31609a405e1fe620a19ffb346' 
  AND token = 'w88kFq0s0BE0C/WRutWBkJNT5BUjlHwaiw8cYfI1Zgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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