SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffd8258b9c28e5695152c452bca753ba48a08d0114ff55096f4cec714ba925b1' 
  AND token = 'QZ4aRIuiqUARtqJ0HQRU4QWXxRpkFpVn/uVLl7mogug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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