SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '47a77bce3323055d32d48e8ed6560f89616e259e259f83cef1948921e76c3f83' 
  AND token = 'aa17ttjTcukZYm7IKIw+5t27lBNp/dspOZ+gP/B4v8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}