SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3643daf6ca0ebbd6d0d85f693348eef8c516d6729e727745e994905152e08c64' 
  AND token = 'a51EvbR5QY9pN5VfjBmwA2GNDyGowCe06o+ls9M5AIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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