SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8429ac7f644e724973af69e7c6809768fbfa391988860ed1ea17a23537b7424c' 
  AND token = 'KnZ4fOlWW4XHKHjQAZ7Uu1Dl89AE6tpeZqbWLxyoLt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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