SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98f0c5e6d071fe2415d0f6fedce15a399c68fcb6f70a6e1ae99926e99f52c94a' 
  AND token = 'CAgRuxIzSlLQx/OLzVZdWGDfx423BwWNkSgQn8nRnGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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