SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40085e0a3d1fd958de746176adae8866d6134ffcae48fac026675bdf30cdb941' 
  AND token = '5GpxBZLClQTK2w4UlW52UmMAsp0Suj4lVQw3J5kyiEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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