SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33068d0c1feb4aa7e8b0ddaf468e53bb86557d0aefc062ba095502df3f2e4925' 
  AND token = 'yJgO6ueOCp7LyZlM5aLJzuT2OkQR3dmakkGle3dXzo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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