SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '907c22b653cf1e872b2986fec66dcdf416a852d6e461eba34334b3708b4a2336' 
  AND token = 'CluC5VcIuWUtzO11cMvBibFTi8RwMSMVpeamHOi6woA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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