SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a6a79f5005c058d052edf19cef2092a9c79514960dcf00c47d6a5773d5602d8' 
  AND token = 'oGry3AKGN62kFbFkiRQoCgkdGDF6BqVb4OgM83pwsCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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