SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '396d1024bb2b66abe09946496bd62226f18f64caff24dcad77ff5b20faec34bf' 
  AND token = '5yCFOorFoA5VG39H1GMKJSMl/C7yM3pzWjNByMZdvKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}