SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '609e0f0b430c7d58f7c9a92c14fbb99cbe72ba4cdba50ece9a602e8f1e17fca6' 
  AND token = 'uHckH5rjMs3seePZQrmiUJ7Ln4j95MkEf0etiVZHKg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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