SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fafe68df48ab65f4cd28768732f6151752a1d9d02f174ed822bbc51b874d89b2' 
  AND token = '/rywfTSXoCrHhCvrj/T+pYTih5YZtBnp+sVuc8Ms65E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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