SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '561a6efd3ca9702d7c4ba4f4c10bbc11024a99d75f5bc9106ea9fb18c6880d33' 
  AND token = 'CIJqvSjh6MrqXhSylw5W+hI1PzmzsgQCcs/fK9yElEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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