SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9da01bf0df16566aecea97d28a702f5308c3ce06a2053edd0d5ebf43e83ca042' 
  AND token = 'Bfyst7Wzg7D54FENKqpE996mQIEJHma8wTReNQRF/xU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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