SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5dfb192d32f84f59ba1f3070359966e82ac524a46719a6748df0c5896021a8db' 
  AND token = 'CNpc5tMO/qYPTY36aL/DHoO+hUUT+fO0GsvZu22k7JU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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