SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '599e8238c3c2d80f8691426f88d2e45a12a4e9d63da00b5cc5f87e10b7556b8e' 
  AND token = 'qJNI0DULwUSFAt8FnYjQx7G3nYk4SLnzjsllfjGWqhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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