SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c202440463a1f339cc0d372c0ae6df25efe663af93c589727e746da963b4f1e7' 
  AND token = 'fD1+diULA3xjfKZuw1E1/lPWrmKZfPxWp6bBq9JGuQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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