SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a05d4e00d4ef357f34df5895ceb7dce290d613ab786dd9f5c287961e65304b51' 
  AND token = 'xtlu0bpIt0JeGHFbz6YPyKND+y1sHtMYEg6eMwXQDOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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