SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd03cc1418aa04b0387838e3234038b351be7fca2e2eea6f2f2b41698bd6b14e' 
  AND token = '2VtxSEkMjNAmmKfcOwU0JlaqlTg3xcg6mvMwUGPhQis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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