SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61d369110d5930d172bc4b2ccd05f301857e9017c4b6eee6f586e4b024d4cebc' 
  AND token = 'kyTmHUjWHbNVG7NvQKZo0D7g79MWvDiCbcDZoyiahIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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