SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffd8722f3c9b554c774d0282868098f1987f568989763e40987c18f236a921b7' 
  AND token = '1ZNk+uhOWLqhwkpmBeSWpOdG3SLNYQahxwyFeMXzUnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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