SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82eee35281383a28e9ef8592aaab7a52011ddc4663b8dffb6c06b6f1c59c45e8' 
  AND token = 'd/ZPVuZ8aLYk9Zh2UOLxPo2hwlGUTDJjsXDW1EzBdAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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