SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af2dde5ebefc416c8a3747fa494ebbf612d333789157b07f1fd9205cd74f92ff' 
  AND token = 'L26L2CPGzyQzpNsaoYdnVj8vGXHQkYpZnOglfRbqZ7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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