SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28088fdcf781beecf31fa32eaf16e0e5fc241301241bc309c2a9f420608053d6' 
  AND token = 'gvV5GlHVLwzMEyhAYQqR6yeSLd6pJXhzbh3XbdVXEXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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