SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde154dbb93eebd698098420ae796034067a4896f6c7e0644716277ab06d57ca' 
  AND token = 'ykISq2KB0TQ370uR7oOo0qCxBjWd6kCATAPNVw4+WxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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