SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d5ebd4a3833714c40be5fdc62b78c36f10a92bcdedcd29a32cf7d3c819f9741' 
  AND token = 'CqepcFMPNzw5dmMFZn+QaKjcoJo7TQxLblvIZUWvb9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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